.login_box {
    width: 100%;
    height: 100vh;
    background-color: #fff;
    background:url('../b_imgs/login.png') no-repeat;
    background-size: 100% 100%;
    display: flex;
}
.b_l {
    width: 50%;
    height: 100%;
    /* background:url('../b_imgs/login.png') no-repeat; */
    background-size: 100% 100%;
}
.b_r {
    width: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
}

.login {
    width: 400px;
    background-color: #fff;
    height: 450px;
    border-radius: 6px;
    border: 1px solid #F1F1F1;
}
.l_top {
    width: 100%;
    height: 50px;
    line-height: 50px;
    background-color: #ccc;
    text-align: center;
    font-size: 20px;
    font-weight: 600;
}
.l_username {
    margin-top: 25px;
    width: 100%;
    height: 50px;
    line-height: 50px;
    display: flex;
}

.user_l {
    width: 120px;
    font-size: 16px;
    color: brown;
    text-align: center;
}
.user_r {
    width: 270px;
    height: 100%;
    display: flex;
    align-items: center;
}
.user_r input {
    width: 240px;
    height: 36px;
}
.l_button {
    margin-top: 100px;
    width: 100%;
    display: flex;
    height: 50px;
    align-items: center;
    justify-content: center;
    color: #fff;
    border: none;
}